In May 2007 Vulpe and i4i successfully sued Microsoft, in the United States District Court for the Eastern District of Texas, for willfully infringing the '449 patent.
In 2009 Judge Leonard Davis, of the U.S. District Court for the Eastern District of Texas, ordered a permanent injunction that "prohibits Microsoft from selling or importing to the United States any Microsoft Word products that have the capability of opening .XML, .DOCX or DOCM files (XML files) containing custom XML," according to an announcement by the plaintiff, Toronto-based i4i Inc.